ES6 .filter在.filter中

Question

因此，我有如下数据：

[
     {
      "id": 0,
      "title": "happy dayys",
      "owner": {"id": "1", "username": "dillonraphael"},
      "tags": [{"value": "Art", "label": "Art"}],
      "items": []
     },
     {
      "id": 1,
      "title": "happy dayys",
      "owner": {"id": "1", "username": "dillonraphael"},
      "tags": [{"value": "Architecture", "label": "Architecture"}],
      "items": []
     },
]

我正在尝试对数组进行筛选，只有当标记数组包含的值是==到另一个字符串时才返回。

这就是我想出的，但似乎仍在发回整个数组：

const tagMoodboards = _moodboards.filter(mb => { return mb.tags.filter(t => t.value == name) })

Answer 1

您不希望在filter中使用filter --相反，在过滤器中，检查tags对象的some是否具有所需的.value属性

​

const _moodboards = [
     {
      "id": 0,
      "title": "happy dayys",
      "owner": {"id": "1", "username": "dillonraphael"},
      "tags": [{"value": "Art", "label": "Art"}],
      "items": []
     },
     {
      "id": 1,
      "title": "happy dayys",
      "owner": {"id": "1", "username": "dillonraphael"},
      "tags": [{"value": "Architecture", "label": "Architecture"}],
      "items": []
     },
];
const name = 'Architecture';
console.log(_moodboards.filter(({ tags }) => (
  tags.some(({ value }) => value === name)
)));

​

Answer 2

要使用filter()，您需要返回真或假的东西--即布尔值。那应该是你第一个开始的地方。所以给出这样的对象

{
 "id": 0,
 "title": "happy dayys",
 "owner": {"id": "1", "username": "dillonraphael"},
 "tags": [{"value": "Art", "label": "Art"}],
 "items": []
},

如果您想决定是否应该使用它，可以在tags数组上尝试使用tags。这将返回一个布尔值。

​

let tags = [{"value": "Art", "label": "Art"}]

console.log(tags.some(tag => tag.value = "Art")) // true

​

有了这一点，您现在可以一起使用filter()和some()了。some()将为数组中的每个项返回true或false，这将确定它是否已过滤：

​

let arr =  [{"id": 0,"title": "happy dayys","owner": {"id": "1", "username": "dillonraphael"},"tags": [{"value": "Art", "label": "Art"}],"items": []},{"id": 1,"title": "happy dayys","owner": {"id": "1", "username": "dillonraphael"},"tags": [{"value": "Architecture", "label": "Architecture"}],"items": []},]

console.log(arr.filter(obj => obj.tags.some(o => o.value == 'Art') ))

​